I work in a hotel in the city and the hotel has something like mushroom vents running out side but they were installed pointing straight out. What is the proper hight and distance from the building that they should be installed. By the way these vents are for oil tanks in the basement.

Since we have no idea where you are located, you should check with your local inspection and permitting dept.

By mushroom vent. I assume that you are referring to the vent caps.(See image)
. If the events are installed horizontally they are installed wrong. They should be installed on the vertical. It should be a simple task to install elbos on them and point them up. Let me know how you make out, good luck, Tom

Frostt is talking about vents for OIL TANKS, Tom. Best advice is as Ma0641 suggested... call local codes enforcement and ask them!

Thanks!